Sedimental

Photograph: Lee Pellegrini

Associate professor of earth and environmental sciences Noah Snyder (left) has begun a two-year, National Science Foundation-funded study to gauge the “human modification of land in the northeastern U.S.”—a project that supported two undergraduate and two graduate research assistants this summer. Above, Kaitlin Johnson, MS’16 (center), positions a high-precision GPS device and Elisabeth Ames, MS’17, bags sediment for radiocarbon dating, along the Souhegan River in Merrimack, New Hampshire, on July 20. Snyder says he has found that “a number of natural-looking river valleys are actually the product of erosion caused by sedimentation behind dams and clearing of forests in the 18th and 19th centuries.”